I am relying on the hazard triangle to come on. MDM does not blink. Since I was deliberately doing an experiment on tracks I am very comfortable with, I was paying attention to the light. Peripheral vision can pick it up easily.

I would not rely on the blinking light for MDM/DSC intervention. In my experience MDM/DSC can do quick corrections without having the warning light flash in the cluster. It is more active than we might think.

Most of the time you can actually feel the intervention in the car's behavior, like a very slight power drop or a slight tug to one side.

Usually when you get the light to flash, it's a big "whoaaa there" intervention.

These responses make me ever more curious about using MDM at the track. I will definitely have to try it for a session at my next event and see how intrusive it is or isn't and how it affects my lap times. As I've posted elsewhere, I once left DSC on by mistake at Laguna Seca in my old 330i and my lap times suffered by 5 whopping seconds. Anyone know how MDM affects your lap times?

These responses make me ever more curious about using MDM at the track. I will definitely have to try it for a session at my next event and see how intrusive it is or isn't and how it affects my lap times. As I've posted elsewhere, I once left DSC on by mistake at Laguna Seca in my old 330i and my lap times suffered by 5 whopping seconds. Anyone know how MDM affects your lap times?

You can't power out and you won't get your line when cornering. These are the only 2 downsides.

I would not rely on the blinking light for MDM/DSC intervention. In my experience MDM/DSC can do quick corrections without having the warning light flash in the cluster. It is more active than we might think...

Could be. I would really like to find documented verification of this somewhere: What exactly does it mean when the warning light flashes?

It definitely takes much longer for the warning light to start flashing in MDM mode than in normal DSC mode. This is why I assume that when the light flashes controls are ON and when the light is OFF controls are not interfering.

Anyway, when I got the car new MDM was peace of mind. Slowly and carefully I have made the transition to DSC off completely. Now I don't use MDM except when it rains (= rarely).

These responses make me ever more curious about using MDM at the track. I will definitely have to try it for a session at my next event and see how intrusive it is or isn't and how it affects my lap times. As I've posted elsewhere, I once left DSC on by mistake at Laguna Seca in my old 330i and my lap times suffered by 5 whopping seconds. Anyone know how MDM affects your lap times?

So, if I follow your posts, you are dismissing DSC-MDM without ever trying it?

MDM does bog you down on exit when you are squeezing on the gas with still some lateral load. MDM's traction circle is significantly smaller than what the tires will allow for sure. My goal this year is to ween myself off the nannies.

I would not rely on the blinking light for MDM/DSC intervention. In my experience MDM/DSC can do quick corrections without having the warning light flash in the cluster. It is more active than we might think.

Most of the time you can actually feel the intervention in the car's behavior, like a very slight power drop or a slight tug to one side.

Usually when you get the light to flash, it's a big "whoaaa there" intervention.

i recommend mdm until you get to the point that you are good enough to notice it intervene and actually prevent you from doing what you intend rather than help.

This. I kept DSC on in my 330 until it got in the way. It did save me a couple of times...I knew I screwed up and didn't have to spin the car to know it. More importantly, cars behind me didn't have to know I screwed up as I spin on the track.

I'm at the point where it really gets in the way. Most times, I forget to turn it off until it intervenes. I don't think the intervention is ever subtle...you can always feel it. Not sure about MDM but it has let me get quite sideways 3 times. Once at the 'ring and twice on a slippery bridge near my house.

Well, since I'm relatively new at all this and it's also my wife's DD I run with MDM on at the track. I notice very little intervention, usually only on slow speed corners where it won't let me rotate the car. For me, the challenge is to be smooth enough to where MDM doesn't kick in and I find this to be a good compromise between lunacy and sanity at the track, for now. That being said, I used to track bikes and truly understand the point of smooth is fast, but don't really care about dropping a $6k bike vs. my baby so think I will still ease into things. Just giving my personal thoughts, as always, to each his own

...I don't think the intervention is ever subtle...you can always feel it. Not sure about MDM but it has let me get quite sideways 3 times. Once at the 'ring and twice on a slippery bridge near my house.

Actually DSC intervenes in different stages.... it's not just on and off. I've noticed the dsc light flashlight when I'm near the edge. If I keep pushing it or if the current dsc isn't effective it will escalate. Mdm has higher thresholds. Sometimes when I'm driving just at threshold of triggering it I notice the dsc light turns on but I don't feel it kick in - if I didn't notice the light I may not have known that dsc is working. One day I may try to add a buzzer or some audible feedback to the dsc light just for fun.

Actually DSC intervenes in different stages.... it's not just on and off. I've noticed the dsc light flashlight when I'm near the edge. If I keep pushing it or if the current dsc isn't effective it will escalate. Mdm has higher thresholds. Sometimes when I'm driving just at threshold of triggering it I notice the dsc light turns on but I don't feel it kick in - if I didn't notice the light I may not have known that dsc is working. One day I may try to add a buzzer or some audible feedback to the dsc light just for fun.

Interesting, for me it is the other way around: I feel it intervening, but do not see the light flashing. Maybe a model year or ZCP thing?

I would not rely on the blinking light for MDM/DSC intervention. In my experience MDM/DSC can do quick corrections without having the warning light flash in the cluster. It is more active than we might think.

Most of the time you can actually feel the intervention in the car's behavior, like a very slight power drop or a slight tug to one side.

Usually when you get the light to flash, it's a big "whoaaa there" intervention.

It can be really different - if you know the Mosport track, MDM always flashes like crazy for me in Turn 2 after 2nd apex (fast downhill sweeper). With it off I just drift a bit more out towards curb - not even rotation - so pretty pointless intervention. In contrast, in Turn 5B (hairpin exit) it allows decent rotation without intervening and sometimes stops it without blinking. It seems to me that it allows much more slip at lower speeds or has it's own weird logic.

The Corvette's "Comp "Mode"is just like our MDM and way too intrusive if you want to work the car on its limit.I used to have a Z06 & a C6 so I have experianced this on those cars.MDM is just about useless with a square setup as it impedes power delivery with the mildest of slip angles.

Based on Steve's description I thought it was not as intrusive as MDM. Well, I guess there is just no way to push a car to the limit and have zero risk...

So, if I follow your posts, you are dismissing DSC-MDM without ever trying it?

MDM does bog you down on exit when you are squeezing on the gas with still some lateral load. MDM's traction circle is significantly smaller than what the tires will allow for sure. My goal this year is to ween myself off the nannies.

I use MDM on the street because you can never predict street conditions, but normally don't drive anywhere near the limits of the M3 on the street.

One of the big reasons I go to the track is to drive the car near its limits and improve my car control skills. So MDM/DSC would be counterproductive. I am though curious to see how it affects lap times.

Based on Steve's description I thought it was not as intrusive as MDM. Well, I guess there is just no way to push a car to the limit and have zero risk...

I have driven Steves car quite a bit and with 560 RWHP it really shows how intrusive these MDM type systems are especially in corners where the car goes light like corner 3 at Mosport.If you run with these systems on you will ever learn proper throttle control on a more powerful car which is critical if you want to get the maximum out of your higher powered rwd car.

It can be really different - if you know the Mosport track, MDM always flashes like crazy for me in Turn 2 after 2nd apex (fast downhill sweeper). With it off I just drift a bit more out towards curb - not even rotation - so pretty pointless intervention. In contrast, in Turn 5B (hairpin exit) it allows decent rotation without intervening and sometimes stops it without blinking. It seems to me that it allows much more slip at lower speeds or has it's own weird logic.

Anyway, I'm still happy it's there.

I see what you mean. I have experienced the same thing at Tremblant. In Turns 1 and 2 that are fast downhill uphill downhill sweepers, the DSC light flickers pretty much non-stop in MDM mode. However I do feel that the car is holding back on power, I don't seem to have as much control with my right foot. With DSC off I feel I can better position the car on a more precise line by modulating the throttle.

BTW, it has been quite a few years since I have driven Mosport. Great track! Gotta love that Turn 2! We are planning to go there this September. Looking forward to it .

Actually DSC intervenes in different stages.... it's not just on and off. I've noticed the dsc light flashlight when I'm near the edge. If I keep pushing it or if the current dsc isn't effective it will escalate. Mdm has higher thresholds. Sometimes when I'm driving just at threshold of triggering it I notice the dsc light turns on but I don't feel it kick in - if I didn't notice the light I may not have known that dsc is working. One day I may try to add a buzzer or some audible feedback to the dsc light just for fun.

I've noticed that on my 330. The light will come on but you won't feel the throttle being cut or the ABS kicking in. I wonder if its just putting DSC in ready mode? Like...ready to save your bacon mode?